I bought them so we could absent ourselves for 10 days or so...Following directions, I found that the main problem was the "crushing" and warping of the bottles - which stopped delivery of the last amount of water altogether after about 4 days. Other ideas...First thing I did is to insert a paper towel to slow the flow (it does!). Then I took a leaf from BABY BOTTLES, that is, they have a plastic liner that collapses as the baby sucks....So, yesterday I took one of those thin plastic supermarket baggies we use for fruits and veggies, made sure it did not leak, and inserted it in the plastic pop bottle, draping the excess over and around the mouth of the 2 liter bottle....Filled it with water (the baggie inside the 2 liter bottle only!), screwed in the spike (still stuffed with a paper towel) so that the baggie is held in place and inserted the whole into a large pot, previously well watered. Two days later, the water is being delivered slowly (the paper towel) and it's not warping it
I am using the watering spikes in large plants that are in pots at my church I can only get their one time during the week to water them so this makes it possible to have live plants at my church, I am also going to use them in some outside planter that always get dry when I am unable to water on a regular time frame.
I think these will work for me since I wanted them to get water to middle and fiber lined bottom of hanging planters but the water runs right through. I don't think they would help if I wanted provide water over a period of time.
it's been very dry in our area so far this season. I decided to try these for things that need lots of watering, like strawberries, grape vines, and tomatoes. They are working great, I fill them in the morning and by evening they are empty, distributing the water by the roots slowly.
I use these all over my yard. I wrap duct tape around the exposed plastic to keep them from deteriorating from sun damage. They keep the water focused to the area I want to saturate. I love them.